ah, Racer, a reactionary! If you only "feel strongly" about a few things, better take guitar music off the list, and substitute something you actually have a clue about. M.Ted is right.
And I, sadly, was wrong :) -- sheesh, I just saw "Eb Bb Cm7" and didn't think about the tune at all. Obviously (well, obvious once you actually stop to think about the melody) the tune is in Bb, not Eb, and the Cm7 is a ii, not a vi. Anyway, my poorly made point was: Think about the function of the chord, rather than getting hung up on the name, because the name on the sheet music is liable to be misleading or just wrong, and the fingering diagrams are often worse.
McGrath of Harlow -- I'd say "chords are not fingering diagrams" in the sense that grammar is not letters on a page, rather than "words are not letters on a page".
The naming conventions aren't really all that variable, they're pretty standardized (at least for the last couple of decades or so). "Cm7sus" is confusing because it doesn't seem to follow the convention when the convention is interpreted literally. OTOH someone familiar with the grammar of chords would understand what was meant. You can't learn the grammar from fingering diagrams, only isolated "words".
OK, the spelling of Sullivan's Lost Chord -- ready? S-U-L-L-I-V...hey, dammit, write this down!! I don't want to have to explain this again!